Prompt
Generate an image of a mature, deciduous elm tree, specifically the Valley Forge Elm (Ulmus americana 'Valley Forge'), standing alone in a open field with a clear blue sky in the background, showcasing its robust growth form and resistant foliage, in a realistic and detailed style, during the fall season with some leaves changing colors, set in a landscape that represents USDA Hardiness Zone 4, highlighting its high disease resistance and suitability for cultivation in North America.